Primary Phase I objective is development, testing and evaluation of a new, more accurate method of radiation detection and monitoring for expression in a new diminutive low-cost device for wearing by personnel working in radiation-exposed environments. In general, the new device would (A) present to the wearer multiple readouts of instantaneous overexposure and continuous accumulated radiation totaled over a preset period of time (up to a year); (B) incorporate at least two alarms, one warning wearer of an instantaneous dangerous exposure level, the other warning that he/she has received or is about to exceed the total accumulated radiation for the time period since resetting of the device. Primary thrust of innovative technology will be use of an insulated gate field effect transistor (IGFET) as a radiation transducer, and its characteristic leakage current as a correlative measurement. X-Ray radiation would be the sole testing mode in Phase I, using state-of-the-art hospital equipment.